The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.
In conventional database systems, users access their data resources in one logical database. A user of such a conventional system typically retrieves data from and stores data on the system using the user's own systems. A user system might remotely access one of a plurality of server systems that might in turn access the database system. Data retrieval from the system might include the issuance of a query from the user system to the database system. The database system might process the request for information received in the query and send to the user system information relevant to the request. The reliable and efficient operation of queries on the database system to deliver information to a user has been and continues to be a goal of administrators of database systems.
Unfortunately, conventional database approaches might process a query relatively slowly if, for example, the query is inartfully drafted or the data is not well adapted to handling queries of a particular kind. A database system may also process a query relatively slowly if, for example, a relatively large number of users substantially concurrently access the database system. These problems have been addressed using custom indexes into the data. The query or a portion of the query is first applied to the index or to a filter and then the index provides limited number of hits with the database to which the rest of the query is applied.